Core: anti-extension
Dead bug
Quick facts
- Beginner
- No equipment
- Core
- Hip flexors
- reps
- ~3 s per rep
This movement is in workout 1
The dead bug is the safest core exercise we use: lying on your back, you lower the opposite arm and leg while keeping your lower back on the floor. It teaches you to stabilise the trunk while the limbs move — which is what the abs actually do in real life and in sport. It suits a sensitive back and serves as the easy substitute for almost every other abs exercise. Reps are counted as the total for both sides.
How to do it
-
Lie on your back, arms pointing straight up, hips and knees bent to 90 degrees — knees over hips, shins parallel to the floor.
-
Press your lower back into the floor and brace: ribs down, no gap between the spine and the floor.
-
Slowly lower your right arm overhead while extending your left leg forward until the heel is just above the floor.
-
Return to the start and repeat with the other arm and leg — that is the next rep.
Coaching cues
- Lower back into the floor
- Slow and controlled
- Opposite arm and leg
Common mistakes
- Lower back lifting as the leg extends
- Moving too fast and too loose
- Holding your breath
Breathing
Exhale as the arm and leg move away, inhale as they return.
Used in courses
Related exercises
FAQ
What are the most common mistakes in Dead bug?
The most common ones: lower back lifting as the leg extends; moving too fast and too loose; holding your breath. Watch for them from the first rep.
What should I focus on during Dead bug?
Keep these cues in mind: lower back into the floor; slow and controlled; opposite arm and leg.
How should I breathe during Dead bug?
Exhale as the arm and leg move away, inhale as they return.
Train it inside a program
Dead bug is part of the Forma. Start: home CrossFit basics course: the app scales reps, rest and load to your level after every session.